有人可以帮我试试看我的RecyclerView吗？如果我不在片段中实现它，似乎。但是，当我尝试将其实现为片段时，我在（CarFront）中的其他XML代码与RecyclerView分开显示。
我在日志中收到此错误： “E / RecyclerView：没有连接适配器;跳过布局”
以下是我的代码，如果您需要任何其他信息或其他代码部分，请随时在下面发表评论。非常感谢你。
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewHolders> {
private List<ItemObject> itemList;
private Context context;
public RecyclerViewAdapter(Context context, List<ItemObject> itemList) {
this.itemList = itemList;
this.context = context;
}
@Override
public RecyclerViewHolders onCreateViewHolder(ViewGroup parent, int viewType) {
View layoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.card_view_list, null);
RecyclerViewHolders rcv = new RecyclerViewHolders(layoutView);
return rcv;
}
@Override
public void onBindViewHolder(RecyclerViewHolders holder, int position) {
//holder.countryName.setText(itemList.get(position).getName());
holder.photo.setImageResource(itemList.get(position).getPhoto());
}
@Override
public int getItemCount() {
Log.e("Test", "" + this.itemList.size());
return this.itemList.size();
}
}
public class Welcome extends AppCompatActivity {
// Declaring variables
private ViewPager viewPager;
private ViewPagerAdapter viewPagerAdapter;
private LinearLayout sectionLayout;
private TextView[] sections;
private int[] welcome_screen;
private Button Skip, Next;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Changing the window to fullscreen
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_welcome);
// Hiding the action bar to make it fullscreen
getSupportActionBar().hide();
// Setting the variables equal to their counter-part in the .xml
viewPager = (ViewPager) findViewById(R.id.view_pager);
sectionLayout = (LinearLayout) findViewById(R.id.sections_layout);
Skip = (Button) findViewById(R.id.skip);
Next = (Button) findViewById(R.id.next);
// Adding the various layouts to the welcome screen
welcome_screen = new int[]{
R.layout.activity_car_front,
R.layout.activity_car_side};
// adding sections
SectionsDesign(0);
viewPagerAdapter = new ViewPagerAdapter();
viewPager.setAdapter(viewPagerAdapter);
viewPager.addOnPageChangeListener(viewPagerPageChangeListener);
//RecyclerView
RecyclerView recyclerView = (RecyclerView)findViewById(R.id.front_recyclerview);
}
public void nextclick(View v)
{
// Checks to see if it has reached the homescreen, if so proceed
int current = getItem(1);
if (current < welcome_screen.length) {
// moving to the next section
viewPager.setCurrentItem(current);
} else {
launchHomeScreen();
}
}
ViewPager.OnPageChangeListener viewPagerPageChangeListener = new ViewPager.OnPageChangeListener() {
@Override
public void onPageSelected(int position) {
SectionsDesign(position);
// When it reaches the last section, show launch button
if (position == welcome_screen.length - 1) {
// last page. make button text to GOT IT
Next.setText("LAUNCH");
Skip.setVisibility(View.GONE);
} else {
// Physical next button (blank for design)
Next.setText("");
Skip.setVisibility(View.VISIBLE);
}
}
// Not using but need
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
@Override
public void onPageScrollStateChanged(int arg0) {
}
};
private void SectionsDesign(int currentPage) {
// Getting how many sections there are
sections = new TextView[welcome_screen.length];
sectionLayout.removeAllViews();
for (int i = 0; i < sections.length; i++) {
sections[i] = new TextView(this);
// Shows how many sections there are
sections[i].setText(Html.fromHtml("•"));
// Size of the sections slider (dot)
sections[i].setTextSize(35);
// For other sections that isn't the one you are on
sections[i].setTextColor(getResources().getColor(R.color.section_inactive));
sectionLayout.addView(sections[i]);
}
if (sections.length > 0)
// Change colour to active
sections[currentPage].setTextColor(getResources().getColor(R.color.section_active));
}
private int getItem(int i) {
return viewPager.getCurrentItem() + i;
}
// Method for switching to the main screen
private void launchHomeScreen() {
startActivity(new Intent(this, Form.class));
finish();
}
public class ViewPagerAdapter extends PagerAdapter {
private LayoutInflater layoutInflater;
public ViewPagerAdapter() {
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
layoutInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View view = layoutInflater.inflate(welcome_screen[position], container, false);
container.addView(view);
return view;
}
@Override
public boolean isViewFromObject(View view, Object obj) {
return view == obj;
}
@Override
// Number of sections
public int getCount() {
return welcome_screen.length;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
View view = (View) object;
container.removeView(view);
}
}
public class CarFront extends AppCompatActivity {
private LinearLayoutManager lLayout;
public static ImageView fbumper;
public static ImageView hood;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//remove title/fullscreen
//requestWindowFeature(Window.FEATURE_NO_TITLE);
//getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
//WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_car_front);
setTitle(null);
List<ItemObject> rowListItem = getAllItemList();
lLayout = new LinearLayoutManager(CarFront.this);
RecyclerView rView = (RecyclerView)findViewById(R.id.front_recyclerview);
rView.setLayoutManager(lLayout);
RecyclerViewAdapter rcAdapter = new RecyclerViewAdapter(CarFront.this, rowListItem);
rView.setAdapter(rcAdapter);
//Selected Images
fbumper = (ImageView)findViewById(R.id.fbumperselected);
hood = (ImageView)findViewById(R.id.hoodselected);
}
private List<ItemObject> getAllItemList(){
List<ItemObject> allItems = new ArrayList<ItemObject>();
allItems.add(new ItemObject("", R.drawable.hood_selected));
//allItems.add(new ItemObject("", R.drawable.hood_card));
return allItems;
}
public static class ViewHolder extends RecyclerView.ViewHolder
{
public ViewHolder(View itemView) {
super(itemView);
}
}
}
<?xml version="1.0" encoding="utf-8" ?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:background="@color/background">
<android.support.v7.widget.Toolbar
android:layout_width="fill_parent"
android:layout_height="45dp"
android:background="@drawable/top_logo">
</android.support.v7.widget.Toolbar>
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="200dp">
<ImageView
android:id="@+id/carfront"
android:layout_width="368dp"
android:layout_height="200dp"
android:scaleType="fitStart"
app:srcCompat="@drawable/carfront"
tools:layout_editor_absoluteY="50dp"
tools:layout_editor_absoluteX="8dp" />
<ImageView
android:id="@+id/hoodselected"
android:layout_width="368dp"
android:layout_height="200dp"
android:scaleType="fitStart"
app:srcCompat="@drawable/hood_selected"
tools:layout_editor_absoluteY="50dp"
tools:layout_editor_absoluteX="8dp"
android:visibility="invisible"/>
<ImageView
android:id="@+id/fbumperselected"
android:layout_width="368dp"
android:layout_height="200dp"
android:scaleType="fitStart"
app:srcCompat="@drawable/fbumper_selected"
tools:layout_editor_absoluteY="0dp"
tools:layout_editor_absoluteX="8dp"
android:visibility="invisible"/>
</android.support.constraint.ConstraintLayout>
<android.support.v7.widget.RecyclerView
android:id="@+id/front_recyclerview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="none" />
</LinearLayout>
public class RecyclerViewHolders extends RecyclerView.ViewHolder implements View.OnTouchListener{
//public TextView countryName;
public ImageView photo;
public ImageView fbumper;
public RecyclerViewHolders(View itemView) {
super(itemView);
itemView.setOnTouchListener(this);
photo = (ImageView)itemView.findViewById(R.id.cardview);
}
@Override
//make a gesture detector
//make a nice clean graphic after they tap on repair, telling the user how it works
//pointer = multitouch
public boolean onTouch(View view, MotionEvent event)
{
switch (event.getAction() & MotionEvent.ACTION_MASK)
{
case MotionEvent.ACTION_DOWN:
actionDown();
break;
case MotionEvent.ACTION_POINTER_UP:
actionUp();
break;
}
return true;
}
// Method for Down Press
public void actionDown()
{
switch (getAdapterPosition())
{
case 0:
CarFront.fbumper.setVisibility(View.VISIBLE);
break;
case 1:
}
}
//Method for Up Press
public void actionUp()
{
switch (getAdapterPosition())
{
case 0:
CarFront.fbumper.setVisibility(View.INVISIBLE);
//break;
case 1:
}
}
}
（我在尝试格式化和解释我的问题时很垃圾。但是，基本上我的RecyclerView没有显示在我的片段中。它是为了显示Cardview / s）
答案 0 :(得分：5)
好的，首先，你的片段结构应该更像下面的结构。在您的onCreateView中，只需夸大布局，然后在onViewCreated中填充/填充您的信息。
我们也使用newInstance，因为这是创建新片段的标准方法。
注意，我使用的是android.support.v4.app.Fragment，而不是较旧的Fragment。
public class CarFrontFragment extends Fragment {
public ImageView bumper; // Do not use static views.
public ImageView hood;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_car_front, container, false);
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
// Bind your views.
RecyclerView list = (RecyclerView) view.findViewById(R.id.front_recyclerview);
bumper = (ImageView) view.findViewById(R.id.fbumperselected);
hood = (ImageView) view.findViewById(R.id.hoodselected);
// Create your layout manager.
LinearLayoutManager layout = new LinearLayoutManager(getContext());
list.setLayoutManager(layout);
// Fetch your items.
List<ItemObject> rowListItem = getAllItemList();
// Set your adapter
RecyclerViewAdapter adapter = new RecyclerViewAdapter(getContext(), rowListItem);
list.setAdapter(adapter);
}
// Creating a new Fragment through newInstance.
public static CarFrontFragment newInstance() {
return new CarFrontFragment();
}
// Fetching items, passing in the View they will control.
private List<ItemObject> getAllItemList(){
List<ItemObject> allItems = new ArrayList<ItemObject>();
allItems.add(new ItemObject("", R.drawable.hood_selected), hood);
allItems.add(new ItemObject("", R.drawable.bumped_selected), bumper);
return allItems;
}
}
现在，对于包含这些的适配器，您需要FragmentStatePagerAdapter。所有这一切都将位置绑定到您选择的Fragment。
public class PagerAdapter extends FragmentStatePagerAdapter {
public static final int NUM_OF_PAGES = 2;
private static final int PAGE_WELCOME = 0;
private static final int PAGE_CAR_FRONT = 1;
public PagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
switch (position) {
case PAGE_WELCOME:
// Return a new instance of your Fragment.
case PAGE_CAR_FRONT:
return CarFrontFragment.newInstance();
}
return null;
}
@Override
public int getCount() {
return NUM_OF_PAGES;
}
}
在适配器中，我们要做的就是通过ItemObject控制的View。
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewHolders> {
private List<ItemObject> itemList;
private Context context;
public RecyclerViewAdapter(Context context, List<ItemObject> itemList) {
this.itemList = itemList;
this.context = context;
}
@Override
public RecyclerViewHolders onCreateViewHolder(ViewGroup parent, int viewType) {
View layoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.card_view_list, null);
RecyclerViewHolders rcv = new RecyclerViewHolders(layoutView);
return rcv;
}
@Override
public void onBindViewHolder(RecyclerViewHolders holder, int position) {
holder.photo.setImageResource(itemList.get(position).getPhoto());
// Telling the holder about the View.
holder.view = itemList.get(position).getView();
}
@Override
public int getItemCount() {
return itemList.size();
}
}
现在，在RecyclerViewHolders中，我们会使用onTouch切换视图的可见性。
public class RecyclerViewHolders extends RecyclerView.ViewHolder implements View.OnTouchListener {
ImageView photo;
public View view;
public RecyclerViewHolders(View itemView) {
super(itemView);
itemView.setOnTouchListener(this);
photo = (ImageView) itemView.findViewById(R.id.cardview);
}
@Override
public boolean onTouch(View view, MotionEvent event) {
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
this.view.setVisibility(View.VISIBLE);
break;
case MotionEvent.ACTION_POINTER_UP:
this.view.setVisibility(View.GONE);
break;
}
return true;
}
}